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R. MAW AND W. B. IVICLEN. SYSTEM 0F OPERATING VEHICLES BY FLUID PRESSURE.v

APPLICATION FILED III/w29, 1914.

I R. MAW AND W. B. NICLEAN. SYSTEM 0F OPERATING VEHICLES BY FLUID PRESSURE.

APPLICATION FILED MAY 29, 1914.

s SHEETSAHEET 2.

Patented Nov. 4, 1919.

lilla@ R. IVIAW AND W. B. IVIcLEAN.

SYSTEM 0F OPERATING VEHICLES BY FLUID PRESSURE.

APPLICATION FILED MAY 29. I9I4.

L. Patented Nov. 4., 1919.

3 SHEETS-SHEET 3.

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l fl or To alt whom z't may concern:

Be it known that we, ROBERT MAW and WILLIAM B. MCLEAN, citizens of the Dominion of Canada, and residents of the city of Montreal, in the Province of Quebec and Dominion of'Canada, have invented certain new and useful Improvements in Systems of Operating Vehicles by Fluid-Pressure, of which the following is a full, clear, and exact description.

This invention relates to improvements in liquid transmission systems of the type comprising a prime mover operating a pump delivering liquid to a motor, which in turn exhausts the pump.

The primary object of the invention is to provide a simple, durable and eiiicient apparatus arranged to deliver varying amounts of liquid per revolution which may he operated in either direction and either as a pump or as a motor.

A further object is to provide a simple and economical method of applying the power delivered by the transmission system to a wheeled vehicle such as an automobile.

Another object is to provide means for varying the speed of the motor without varying the speed of the prime mover and the pump.

Still another object is to provide in a liquid transmission system means for starting the prime mover, means for operating the motor independently as when coasting, l

and means for reversing the motor without correspondingly reversingl tlieprime mover or pump.

The means for accomplishing the foregoing and other objects comprises essentially a prime mover connected toa variable stroke pump, which delivers liquid under pressure to a suitable motor or to a suitable high pressure tank, and draws liquid from the exhaust side of the motor or from a low pressure tank, so that a constant circulation of the same liquid is maintained. A cross over isprovided in the connections between the pump and tanks, so that high pressure fluid may be passed through the pump to operate t e saine as a starting motor tor the prime mover, when the same is an internal combustion motor or other mechanism requiring an initial revolution. Means are also provided for reversing the Specication of Letters Patent.

Application led Hay 29, 19M. Serial No. @1,9872

liquid back to the intake of the Patented Nev. e, wie.

How of liquid through the connections whereby the motor may be operated in either directionwithout changing the direction of revolution of the pump and prime mover, and also means for permitting a free circulation vof the liquid through the motor without flow through the pump. The pump which is Adirectly connected to the prime' mover is arranged so that the stroke o its moving parts'may be varied in order t o produce a variation in the quantity of liquid circulated, while maintaining a uniform speed of revolution. The motor for convenience and direct application of power is built directly into the wheels.

In the'drawings which illustrate V'the invention:-

Figure 1 is a diagrammatic plan view showing the application of the system to an automobile.

Fig. 2 is a vertical long'tudinal section of the pump. Y

Figs. 3, 4, 5 and 6 are sections on the lines 8f3, 4 4, 5-5 and 6-6 respectively of Fig. 2.

Fig. 7 is a vertical section through the center of a motor.

Figs. 8 and 9 are sections on the line 8--8, and 9 9 respectively, Fig. 7.

Referring more particularly t0 the drawings, 11 designates the prime mover which in the drawings is shown to be the internal combustion engine of an automobile, and 12 a liquid pump operated thereby and preferably-direct connected thereto, so that the revolving members of the pump replace the Hy wheel of the engine. The pump delivers liquid through pipe 13 to motors 12, which may be separate from or built into the wheels of the vehicle. The delivery from the pump is through the pipe 13, and after the liquid has passed through the motors, it is exhausted into the pipe 14 and returned to the intake of the pump 12. A check valve 15 is provided in Jthis pipe to prevent reyerse fiow of the liquid, and a by-pass 16 is provided around the check valve in order that such reverse low may be permitted when necessary, as for example, when the vehicle is being backed. A supply of liquid somewhat in excess of what is required for actual circulation is maintained in high and low pressure tanks 17 and 18 respectively,

the pump being arranged to deliver into the for freely circulating the liquid. Thisv high pressure t ik through pipe 19 and draw from the low pressure: tank through pipe 20. These pipes are provided ivlth check valves 19a and 20a respectively, which preventreverse flow of thevfluid. As liquids are practically incompressible, 1t will be understood that these tanks normally contain air or other gas above the liquid,

ot' the tank. This feature is utilized for driving the pump as a motor, so that the pump may be used as a starting devicefor the internal combustion motor 11. It is of course necessary that the pump should" run nl its normal direction. To obtain this relsuit, cross over pipes 21 are provided hetween the pipes 19 and 20, each leading from the front of the check valve in one pipe t'fthe rear of the. check valve in the other pipe. as clearly shown. These cross over pipes are provided with valves 22 simultane- 1 ousllv operable'by means of a lever 23 con-` It 1s customary whenl veniently located. traveling down hill in `automobiles or other power vehicles to stop the prime mover for the purpose of saving fuel. In .the present arrangement, stopping of the prime mover produces a stopping of the pump, so that the oil will not be circulated thereby. As. however, the Wheelsv continue to revolve and produce movement of the motors therein,

: these motors will operate as pumps, and it is therefore necessary to provide a means means consistsof a ley-pass pipe 24 which short. circuits the pump in so far as the motors are concerned and permits a free liovvv of the liquid between the intake and exhaust of the motors. As a precaution. a relief valve 25 may be provided which will permit. the escape of the transmission liquid from the delivery to the intake side of the pump, if the resistance to the operation of the pump or motors should be so great as to cause dangerously high pressures. The variable stroke pump, which is th most important element of the system, comprises a fixed casing 26 containing a casing 27 direct connected to the shaft 28 of the prit-.e mover 11, and revolubly mounted on a cent-ral shaft 29 by means of ball bearings 30. The central shaft 29 is held against revolution, but. is permitted a lateral sliding movement, so that itv can be moved fromv a position concentric with the casing 27 to eccentric positions on either side of the center thereof. The shaft 29 carries revolubly mounted thereon within the casing 27 a cylinder member 31 having a plurality of bores 32- arranged radially of the shaft 29. Each cylinder is provided with a piston4 33 having at the outer end thereof an enlarged within athel casing .27 and arranged perpendicular .to the radii thereof. jThe shaft 291s hollowed out toprovidc-inlet 'and out'- let passages 36 and A37 arranged to each connect withL an equal number of cylinders`at one time. These passages are obviously spaced suiicientl'y apart .to prevent. both passages coming Vinto commuuicatlon .with a single cylinder.` Ports 38 are provided at the inner ends of the cylinders, and 'as the cylinder member revolves, are broughtal-A ternately into communication with the inlet and outlet passages. The-suction andA discharge pipes 39 and 40.01 Vthe pump Vare connected to; theshaft! 29 at right angles Athereto, as clearly shown m Figs. 2 and 4,'

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and are rigidly connected to the shaft by a Y "clamp 41. V`VA control lever 42 conveniently locatedron the vehicle is connected to one,

or Vboth'of these pipes by aclamp 43 (Fig.

' 1), so that by operating the lever, the pipes may be shifted toV produce. bodily lateral movement of the shaft 29. This movement controls the amountof eccentricity of the shaft with respect to the rcvoluble casing 27, andalso the position of the shaft center to one side or the other of the casing center.'

It will be readily understood that if the shaft is moved into position concentric with the casing, there will be no yrelative mov ment betWeen-thecylinders carried bythe shaft, and the pistons carried by the casing. so that no flow of liquid will result.` If, however, the shaft is moved to eccentric position, reciprocating movement between the cylinders and pistons will be produced by the rotation of the casing, thus causing the liquid to be drawn into the cylinders on one side of the shaft and expelled from the cylinders 'on the opposite side. Assuming the relation of the part-s for revolution in a VVpositive direction to be as shown in Fig. 3,

in the directionvof rotation of the casing.

This reverse direction of liquid flowl will obviously operate the motors connected theretoin the reverse'direction. As check valve 15 normally prevents reverse (or pressure) How through the pipe 39, by-pass 16 is provided with a manual control val-.fe whereby valve 15 may be shunted and reverse How through p'pe 39 thereby permitted,'for. the purpose described.

The motors 12, which drive the vehicle, may be located and arranged in any suitable manner, but it is preferred to use a motor built into and forming a part ofthe driving wheels, as by this means the power is applied directly to the wheel and not through intermediate mechanism; The mo` tors, which are shown in Figs. 7 to 9 inclusive, cach include a felly 45 connected by plates or spokes 46 to a hub 47, which revolves on ball bearings 48 on a fixed shaft 49. The extremity of the shaft 49 within the wheel is provided with a fixed eccentrically disposed portion 50, which being eccentric to the shaft is also eccentric to the felly of the wheel. rllhis eccentric 5,0 earries a revoluble cylinder member 51 containing reciprocating pistons 52 mounted at their outer ends in guides 53 fixed to the felly 45, in exactly the same manner as already described in connection with the pistons and guides of the pump. The ends of the shaft are hollowed out to provide inlet and outlet passages 54 and 55 respectively for the motive fluid, which flows through vports 56 in theeccentric and ports 57 in lthe cylinder member.

. The supply and exhaust pipes 58 and 59 respectively are secured to the shaft by means of a suitable clamp 60, and preferably extend parallel with the shaft 49 from Wheel to wheel.

When the motive fluid is supplied to the motor, under pressure, it presses in opposite directions against the cylinders and pistons in the well known manner and forces same apart, which longitudinal movement is transferred by reason of the eccentricity of the felly carrying the pistons and shaft. carnving` the cylinders into a rotary movement of the felly, so that the vehicle is caused to travel.

If the cylinders normally expelling liquid receive same under pressure and the cylinders receiving liquid under pressure have the liquid drawn away from them by suction, it is obvious that the motor will operate in a reverse direction. rl`hus, reversal of direction of the liquid flow caused by shifting the shaft of the pump from one side to the other of the casing center will produce revolution of the motors in a reverse direction, while the pump continues to revolve in the same direction. As will be readily seen from Fig. 1 and Fig. 2, the intake pipe 36 of the pump is connected to thev exhaust pipe 59 of the motors from the pipe 14 at one end, and at the other end to the pipe 20 from the low pressure tank while the discharge pipe 37 of the pump is connected at one end to the supply pipe 58 of the motors through the pipe 13 and at the opposite end through the pipe 19 to the high pressure tank 17. Thus, when the vehicle is running, the liquid will circulatey through the pump and motors, While the liquid in the tanks and other connections will remain substantially immobile. When the cross over 'pipes 21 are utilized, the high pressure fluid is delivered to the intake pipe 36 of the pump, which then becomes a motor and imparts initial revolution to the prime mover 11. That is, liquid from tank 17 is expelled to and through pipe 20 and into the pump, which is thereby rotated, and the liquid thence expelled through pipe 19 by way of the cross-over to pipe 20 in rear of check valve 20, and so to the low pressure tank 18. When the vehicle is run` ningv with the prime mover and pump stopped, the exhaust from the wheel motors circulate through the pipes 14, 39 and 20 to the pipe 24, and then through the pipes 19, 40 and 13 back to the intake of the motors, so that the liquid circulates freely and the operation of the motors does not act as a brake onl the vehicle. It will be seen that pipes 39, 40 are continuous through the pump and that the flow passages 36 and 37 of the pump are merely tapped 'off these pipes, so that the liquid merely flows past the pump and not through it. When the pump is not running, the liquid in the pipes 13, 14, 19 and 20 between the pump and the by- .pass pipe 24 is stagnant and will therefore move without resistance in whatever direction it is impelled by the discharge of the wheel motors. lf, however, the by-pass 24 be partly closed, the circulation of liquid will be impeded so that the motors will operate against resistance and hence produce a certain braking effect on the vehicle.

Certain of the subject-matter shown in the accompanying'drawings and described iny the preceding specification is claimed more specifically in the copending applications` filed May 29, 1914, Serial Nos. 841,968 and 841,969. y y

Having thus described our invention, what we claim is:

1. A device of the character described, comprising the combination with a vehicle and a prime mover therein, of a pump driven by said prime mover, motors con` nected to the wheels of said vehicle, conduits connecting said pump and motors for the supply and return of fluid, and means for stopping the vehicle including high and low pressure reservoirs and means for connecting the high pressure reservoir with the 'discharge side of thel wheel motors and the low pressure reservoir with the intake side of the wheel motors.

2. In an automobile, the combination with the driving wheels and engine, of a liquid pump direct connected to the engine, motors direct connected to the wheels, a conduit connecting the discharge side of the pump passing the check valves between said tank conduits arranged to connect the high pressure tank with the suction side of the pump and the low. pressure tank with the discharge side of the pump.

3. In an automobile, the combination with the driving wheels and engine, of a liquid pump direct connected to the engine, motors direct connected to the wheels, a conduit connecting the discharge side of the pump with the supply side of the motors, a conduit oonnecting the exhaust side of the motors with the suction side of the pump, a high pressure tank and a low pressure tank, a conduit connecting the high pressure tank with the discharge side of the pump, a conduit connectin r the low pressure tank with the suction site of the pump, check valves controlling the direction of liquid circulation in said conduits and a cross over connection between said tank conduits located between the pump and check valves and arranged to connect the suction and discharge sides of the pump.

4.. In an automobile, the combination with the driving wheels and engine, of a liquid pump direct connected to the engine, mor

tors direct connected to the wheels, a conduit connecting the discharge side of the pump with the supply side of the motors, a conduit connecting the exhaust side of the motors with the suction side of the pump, a high pressure tank and a low presure tank, a conduit connecting the high pressure tank with the discharge side of the pump, a con duit connecting the low pressure tank with the suction side of the pump, check valves controlling the direction of liquid circulation in said conduits, and means for rever-sing the direction of vehicular' movement including a by-pass conduit arranged to establish liquid flow in a reverse direction between the pump and motors.

5. In an automobile, the combination with the driving wheels and engine, of a liquid pump direct connected to the engine, motors direct connected to the wheels, a conduit connecting the discharge side of the pump with the supnlv side of the motors, a conduit connecting the exhaust side of the motors with the suction side of the pump, a lngh pressure tank anda low pressure tank,

a conduit connecting the high pressure tankA over connection between said tank conduits located between the pump and check valves and arranged to connect the suction and discharge sides of the pump.

In a vehicle, the combination with the running wheels and an engine carried by the vehicle, of a liquid pump direct connected to the engine, motors direct connected to the wheels, a conduit connecting the discharge side of the pump with the supply side of the motors, a conduit connecting the exhaust side of the motors with the suc# tion side of the pump, a high pressure tank and a low pressure tank, a conduit connec-ting the high pressure tank with the discharge side of the pump, a conduit connecting the low pressure tank with the suction side of the pump, check valves controlling the direction of liquid circulation in said conduits, means for varying the speed and direction of travel of the vehicle from nothing to maximum in either direction without varying the speed or direction of rotation of the engine, includin means for shifting the pump axis relative y to its axis of rotation, and a by-pass conduit arranged to establish a reverse iow of liquid between the pump and motors.

In witness whereof, we have hereunto set our hands in the presence of two Witnesses.

ROBERT MAW. WILLIAM B. MGLEAN. Witnesses:

S. R. W. Ammin, G. MORELAND. 

